[u801e]

> crossing traffic at a diagonal like that

I believe you misunderstood what I was trying to convey. What I was saying was that the cyclist should change lanes to the one corresponding to their desired direction of travel through the junction (like one would do when in a car or on a motorcycle).

> means that drivers will need to look almost 180 degrees behind them to spot you.

Why couldn't they use their mirrors?

[Doxin]

You're right, crossing isn't the right word here. The point largely stands though: merging into a lane of car traffic is dangerous as a cyclist.

> Why couldn't they use their mirrors?

They can, but don't. People look in their mirrors for cars, not for cyclists. This is the same problem as cars overtaking cyclists and then making a right turn as if the cyclist isn't there.

In general you want to separate traffic that goes as different speeds. There's no good reason to mix bicycle traffic into car traffic: there are alternative solutions that avoid doing so.

[u801e]

> merging into a lane of car traffic is dangerous as a cyclist.

Not really. You really only need to check your mirror, then look back and be certain drivers approaching from the rear see you and slow down. Only then should you change lanes.

> People look in their mirrors for cars, not for cyclists.

That would only apply if the cyclist was overtaking (which isn't a common situation). Besides, motorcyclists ride in traffic and Ste seen.

> In general you want to separate traffic that goes as different speeds.

Limited access highways/motorways accommodate traffic going at significantly different speeds. For example, on uphill grades, trucks can be going as slow as 60 km/h whole faster traffic is going 120 km/h. On the unlimited sections of the Autobahn, trucks are limited to 80 km/h and faster traffic may be going around 150 km/h.

Given those examples, there should be no issue with cyclists going 15 to 40 km/h among faster traffic going 30 to 80 km/h.

> There's no good reason to mix bicycle traffic into car traffic: there are alternative solutions that avoid doing so.

The only solution that would work is a completely separate path with infrequent intersections and little to no pedestrians.

Once there are frequent intersections, then there are conflicts unless separate traffic signals with exclusive phases are used (which leads to more delays and noncompliance).

Side paths van work at lower speeds (15 km/h or less), but those speeds won't work for the distances people need to travel unless they're willing to invest significantly more time in traveling compared to other modes of transportation other than walking.

For example, my bicycle commute in the afternoon involves riding from work to my childrens' school, picking them up, taking them to an after school program, and then riding back home. The total distance I have to cover is 15 miles. While moving, I average about 11 mph. My lowest speed up hills is about 5 mph. My top does downhill is about 27 mph. Almost all of my commute is on roads with traffic where I take the lane while riding.

If I rode at 16 km/h or less on this commute, them I would never be able to get the kids to their destination on time.

So, from a transportation point of view, using the roads where I can ride at higher speed safely is the best and safest option.